Starting and stopping mechanism



y 18, 1937. w. E. NALJGLER- l 2,080,544

STARTING AND STOPPING MECHANISM Filed Oct. 11, 1954 2 Sheets-Sheet 1Fig.1. 46, 2b /9 e3 27 I0 30 as 94 Amy/727?.

y 1937. w. IE NAUGLER 2,080,544

STARTING AND STOPPING MECHANISM Filed Oct. 11, 1934 2 Sheets-Sheet 2WVEA/TUF.

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Patented May i8, 193:?

STARTING AND STOPPKNG MECHANESM Application October 11, 1934, Serial No.747,991

9 Claims.

This invention relates to starting and stopping mechanisms and is hereinillustrated as embodied in mechanism developed for stopping and startinga machine for lacing the uppers of shoes preparatory to lasting. Theillustrated mechanism was designed particularly for use in a machine forthe above purpose disclosed in an application for Letters Patent of theUnited States Serial No. 21,011, filed May 11, 1935, in the name ofJoseph Fossa. The mechanism is, however, applicable tomany other typesof machines.

It is an object of this invention to provide an improved starting andstopping mechanism by which a machine may be started and be graduallybrought up to normal operating speed without objectionable shock and bywhich, after the machine has been slowed down gradually to a moderatespeed, the machine will be brought to a stop in a definite position inits cycle of operation, likewise without objectionable shock.

With the above object view, a feature of the invention consists in thecombination, with a suitable stop mechanism, of a frictional drivingconnection, the friction of which is preferably adjustable, a positivedriving connection, preferably between the frictional driving connectionand the shaft of the machine to be driven, and means for rendering thepositive connection either operative or inoperative, the frictional andpositive connections acting mutually, when the positive connection isrendered operative, frictionally to connect the source of power, such asa rotating pulley, with the shaft of the machine to be driven. When soconnected, slippage will occur initially in the frictional drivingconnection as the machine starts to be driven but, as the machinegathers speed, this slippage is progressively decreased to zero and thefriction of the frictional driving connection then serves to drive themachine at the speed of th pulley, with the machine under normal load,although permitting slippage so as to prevent damage to the machine ifthe machine should become overloaded.

In order to slow down the machine gradually simultaneously withrendering inoperative the positive driving connection, and subsequentlystop its shaft in a definite angular position, another feature of theinvention consists of a cam, a cam lever and associated mechani m whichact to ap ply a brake with gradually increasing force and in which thecam track of the cam is constructed with a stop shoulder whichcooperateswith the cam lever in such a manner as to serve as a positivestop for stopping the machine shaft in a definite angular position. Withthis feature, means are provided to move the cam lever and cam trackrelatively into and out of operative engagement with each other.

Another feature of the invention consists in a single member, such as asleeve, arranged to slide from one position to another upon the shaft,either automatically or under control of the operator, so that, whenslid into one position, it disconnects the brake members and renders thepositive driving connection operative between the machine shaft and thefrictional driving connection, whereby the friction will drive themachine, and which member, when slid into the other position,disconnects the positive driving connection from the frictional drivingconnection and operates the above mentioned braking and stoppingmechanism.

The invention will be understood upon reference to the accompanyingdrawings, in which Fig. 1 is a front sectional view, taken on the lineI--I of Fig. 3, looking in the direction of the arrows, and with theparts in a position about before stopping takes place;

Fig. 2 is a sirm'lar view of a portion of the mechanism shown in Fig. 1but with the parts in stopped position;

Fig. 3 is a sectional view, on a reduced scale, taken on the lineIII-III of Fig. 1, looking in the direction of the arrows and showingthe brake mechanism in detail;

Fig. 4 is a front elevation, on a reduced scale, of the parts in drivingposition, with some of the parts cut away to show certain parts insection, and

Fig. 5 is a sectional view, on a reduced scale, taken on the line V-V ofFig. l, and showing the frictional driving connection.

Referring to the drawings, i9 is the main shaft of the machine to bedriven and stopped by the Al mechanism of the present invention. Mountedto turn with the shaft and to slide thereon is a sleeve l2, which hastwo arcuate recesses l3 cast in it to reduce its Weight. The shaft andsleeve are connected together by keys [4, secured in I8. The oppositeend of the spring rests against the end I9 of the bore 28. The portionof the sleeve extending beyond the end of the bore is drilled to form asliding fit at 22 on the reduced portion I of the shaft. The compressionspring I8 thus tends to force the sleeve outwardly on the shaft whenpermitted to do so. Mounted to turn on a reduced portion 23 of thesleeve is a loose pulley 24. The pulley is maintained in longitudinalposition relatively to the shaft by means of an easily assembled anddisassembled circular tongue and groove connection. The groove is formedbetween a collared bushing 26, resting against a second shoulder 21 onthe shaft, and a washer 28 which is clamped against the bushing 26 bymeans of a nut 36 threaded upon the extreme outer end of the shaft I0.The tongue, which is a running fit in the groove, is formed by a washer32 secured to the hub of the loose pulley 24 by means of screws 34.

Mounted on the loose pulley 24, in a suitable recess, is a cup-shapedbushing 36. This bushing is frictionally connected to the loose pulleyby means of friction members 38. (see Figs. 1 and 5) which arepositioned in slots 39 in the pulley and which are riveted to a clampring 48 made in sections and connected by means of adjusting screws 42and nuts 44. This frictional driving connection between the loose pulley24 and the bushing 36 will be referred to later. The outer end of thebushing 36 is provided with arcuate slots 46 into which the ends of pins48, securely mounted in bores in the sleeve I2, will enter when thesleeve I2 is permitted to slide along the shaft outwardly by means ofits spring I8.

The position of the sleeve I2 is controlled by means of a controllingrod 58 mounted to slide vertically in a bracket 5I secured to the frame52 of the machine. This rod 56 may be either operator or machinecontrolled and cooperates with a cam slot 53 in the sleeve I2. Assumingthat the upper end of the rod 50 is in its uppermost position or in theslot 53, with the machine in stopped position, it will be seen that,upon withdrawing the rod downwardly from the cam slot 53, the spring I8will slide the sleeve I2 longitudinally along the shaft I0 toward itsouter end so that, as the loose pulley revolves, carrying with it by thefrictional driving connection the cup-shaped bushing 36 with the arcuateslots 46, the ends of the pins 48 will enter these slots. When the rearends of the slots 46 strike the pins 48, a positive driving connectionis established between them, or between the bushing and the sleeve,which connection will drive the sleeve from the rotating pulley 24 andthereby the shaft to which the sleeve is non-rotatably connected.However, the friction members 38 are intended to be so adjusted by meansof the screws 42 that slippage will take place in the frictional drivingconnection between the bushing 36 and the pulley 24 upon starting andalso for a short period thereafter. However, this friction should beadjusted so that it will maintain the shaft I6 and the machine connectedthereto at its proper speed without slippage after such speed has beenattained with full load on the shaft. With such an adjustment theslippage in this frictional connection will gradually decrease to zeroas the shaft gathers speed. Obviously, when this slippage is zero, theshaft and the machine will be driven at the speed of the pulley.Furthermore, if for any reason the r machine is given an excessive load,the friction,

being properly adjusted, will not be sufficient to drive the machine andcause injury to its parts.

In a large number of machines it is necessary to stop them in a definiteangular position and, in order to meet this requirement in the presentinvention, a novel brake and stopping device is provided to operate withsaid positive driving connection. This brake and stopping device arebest shown in Fig. 3, although some of its features are shown in Fig. 1.This mechanism will now he described.

Secured to the shaft III is a brake drum I0 and surrounding the drum isa brake band 12 which has frictional material 14 secured to its innerface. One end of the brake band I2 is freely mounted on a pin I6,passing through the bifurcated end I8 of a lever 80. The lever 80 ispivotally mounted on a fixed pivot 82 secured, preferably, to a portionof the machine frame 52. Also loosely mounted on the pin 16 is a camlever 84 having a cam face 86. Mounted in the, cam lever 84, and securedthereto by a clamp screw 81 is a pin 88 which is parallel to the pin I6.Mounted to swivel on the pin 88 is a block 98 having an aperture throughwhich the threaded portion of an adjusting screw 92 passes freely. Thisscrew is threaded through a block 94 connected by means of a pivot pin96 to the opposite end of the brake band I2. The diameter of the brakeband, i. e. its curvature, is determined byadjusting the screw 92 and,in order to maintain the band in concentric relation with the brakedrum, two adjustable stop screws 98 and I06 are provided on which twoseparated portions of the brake band rest. These stop screws and thepivotal mounting of the band on the lever 86 andv the pivotal mountingof this lever itself permit the brake band to float freely withoutnormally touching the brake drum I2.

When it is desired to stop the machine, the control rod 56 is permittedto be lifted by a spring I86, either automatically or by control of theoperator, and the end of this rod engages the outer surface of thesleeve I2 until the cam slot reaches such a position that the upper endof the rod will enter the cam slot. The shape of the cam slot is suchthat, upon continued rotation, the sleeve I2 is brought inwardly (to theleft in Fig, 1) to disconnect the pins 48 from the ends of the slots 46,thus stopping the drive of the shaft from the pulley 24. As thisdisconnection takes place, a second cam I I2 cut on the sleeve I2, hasbecome positioned beneath the cam lever 84 so that the cam face 86thereon starts to ride upon the track of the cam H2. The cam face 86 islifted by a. gradual rise in the cam track which causes the cam lever 84to pull on the adjusting screw 92, through the pin 88 and swivel block98. The screw 92 then pulls on the block 94 and pivot 96 to contract thebrake band so that its friction surface I4 engages the brake drum withincreasing force to slow down the rotation of the shaft. The end of thecam track is steep to form a shoulder or abutment i M which, when itstrikes the cam face 86, stops the machine in a definite angularposition. As the speed has been reduced gradually by the increasingforee by which the brake band has been contracted, this final stoppingat a definite angular position is without substantial shock.

When the machine is started again by the withdrawal of the controllingrod 56 from the cam slot 53, the spring I8 in sliding the sleeve 52 (tothe right in Fig. 1) not only causes the pins 48 to engage the slots 46but it also causes the cam M2 on the sleeve to withdraw from beneath thecam lever 84, releasing the brake which then expands due to theelasticity of the brake band F2 to clear the brake drum.

Having described my invention, what I claim as new and desire to secureby Letters Patent of the United States is:

1. A starting and stopping mechanism having, in combination, a shaft, aloose pulley, a frictional driving connection, a'positive drivingconnection, means for rendering the positive driving connection eitheroperative or inoperative, said driving connections acting mutually, inseries, when the positive connection is rendered operative, to connectthe pulley and the shaft so that the pulley will start the shaft anddrive it, after the slippage in the frictional connection hasprogressively decreased to zero, at its normal speed, a brake forslowing down the shaft, mechanism for applying the brake withcontinuously increasing force, and a stop for finally stopping the shaftin a definite angular position while said force is continuouslyincreasing.

2. A starting and stopping mechanism having, in combination, a shaft, abrake member secured thereto, a contractible brake member adapted toengage the first mentioned brake member for applying a braking force, amember mounted to turn with the shaft and having a cam track, a camlever having a surface to engage the cam track, mechanism associatedwith the cam lever for contracting the contractible brake member withcontinuously increasing force to slow down the shaft, and a stopshoulder at the end of the cam track, said surface on the cam leverengaging said shoulder to stop the shaft in a definite angular positionwhile said force is continuously increasing.

3. A starting and stopping mechanism having, in combination, a shaft, abrake member secured thereto, a second brake member adapted to engagethe first mentioned brake member for applying a braking force, a membermounted to turn with the shaft and having a cam track, a cam leverhaving a surface to engage the cam track, mechanism associated with thecam lever for causing engagement of the two brake members withincreasing force to slow down the shaft, a stop shoulder at the end ofthe cam track, said surface on the cam lever engaging said shoulder tostop the shaft in a definite angular position, and means to move the camlongitudinally on the shaft into and out of operative engagement withthe cam lever.

4. A starting and stopping mechanism having, in combination, a shaft, abrake drum secured thereto, a floating contractible brake bandsurrounding said drum, adjustable means for changing the curvature ofthe band to maintain it normally in substantial concentric relation withthe drum and out of contact therewith, a cam mounted to turn with theshaft, a cam lever cooperating with the cam for contracting the brakeband with increasing force into contact with the brake drum to reducethe speed of the shaft, and a stop on the cam for finally stopping theshaft in a definite angular position.

5. A starting and stopping mechanism having, in combination, a shaft, abrake drum secured thereto, a floating contractible brake band.surrounding said drum, adjustable means for changing the curvature ofthe band to maintain it normally in substantial concentric relation withthe drum and out of contact therewith, a cam mounted to turn with theshaft and to slide thereon, a cam lever cooperating with the cam forcontracting the brake band with increasing force into contact with thebrake drum to reduce the speed of the shaft, a stop on the cam forfinally stopping the shaft in a definite angular position, and means toslide the cam along the shaft out of contact with said cam lever torelease the brake as the shaft is started.

6. A starting and stopping mechanism having, in combination, a shaft, aloose pulley mounted to turn about the shaft, a cup-shaped bushingmounted on the pulley, a frictional driving connection between thepulley and the bushing, a sleeve mounted to turn with the shaft and toslide thereon between a stopping position and a driving position, aspring for sliding the sleeve into one of said pbsitions, a cam on thesleeve for sliding it into the other position against the action of thespring, means cooperating with the cam to control movement of thesleeve, and a positive driving connection between the bushing and sleeveoperative only when the latter is in driving position, whereby, when thesleeve is; in driving position, the pulley will start the shaft anddrive it, after the slippage in the frictional connection hasprogressively decreased to zero, at its own speed.

'7. A starting and stopping mechanism having, in combination, a shaft, aloose pulley mounted to turn about the shaft, a cup-shaped bushingmounted on the pulley, a frictional driving connection between thepulley and the bushing, a sleeve mounted to turn with the shaft and toslide thereon between a stop-ping position and a driving position, aspring for sliding the sleeve into driving position, a cam on the sleevefor sliding it into stopping position against the action of the spring,means cooperating with the cam to control movement of the sleeve, and apositive driving connection between the bushing and sleeve operativeonly when the latter is in driving position, whereby, when the sleeve isin driving position, the pulley will start the shaft and drive it, afterthe slippage in the frictional connection has progressively decreased toZero, at its own speed.

8. A starting and stopping mechanism having, in combination, a shaft, abrake member secured thereto, a second brake member adapted to engagethe first mentioned brake member for applying a braking force, a loosepulley, a member mounted on the pulley, a frictional driving connectionbetween the pulley and the member, a sleeve mounted to turn with theshaft and to slide thereon from one position to another, means on thesleeve, which are operative only when the sleeve is in one of saidpositions, for positively connecting the member and the sleeve, wherebythe pulley, operating through said frictional connection and said means,will start the shaft and drive it, after the slippage in the frictionalconnection has progressively decreased to zero, at its own speed,additional means on the sleeve, which are operative only when the sleeveis in the other of said positions, for causing engagement of the twobrake members with increasing force to slow down the shaft, and a stopfor finally stopping the shaft in a definite angular position.

9. A starting and stopping mechanism having, in combination, a shaft, aloose pulley mounted to turn about the shaft, a member.

mounted on the pulley, a frictional driving connection between thepulley and the member, a

sleeve mounted to turn with the shaft and to slide thereon between astopping position and a driving position, a spring for sliding thesleeve into driving position, a cam on the sleeve for sliding it intostopping position against the action of the spring, means cooperatingwith the cam to control movement of the sleeve, a positive drivingconnection between the member and sleeve operative only when the latteris in driving position, a brake drum secured to the shaft, acontractible brake band surrounding said drum, a second cam on thesleeve, a cam lever to cooperate with the second cam, and a stop on thesecond cam, all being so constructed and arranged that, when the sleeveis in said driving definite angular position, and afterward, when 10 thesleeve is slidagain into driving position, the second cam will slidefrom under its cam lever to release the brake.

WALTER E NAUGLER.

